THE OPEN-HEARTH FTJHNACE. 149 Several years ago I published an investigation into the calorific balance of an open-hearth furnace.* Quite recently other experiments have been conducted by von Juptner,t and as our results did not agree, I have made a new determination. There are at Steelton two acid-lined 50-ton furnaces, running on a coal consumption of 500 pounds per ton of steel. Deducting for idle time leaves 440 pounds (200 kg.) for heating and melting. The heat from internal combustion is shown by the following comparison of the data given by von Jiiptner and the old experiment at Steelton: Element oxidized. Per cent, of total charge. Jiiptner. Steelton. Si Mn 0 Fe 0.48 1,23 1.03 2.24 0.41 0.88 0.95 0.98 According to Jiiptner the value of this combustion was 169,560 calories per ton of steel, while at Steelton it was 143,000 calories, the difference being due to the greater loss of iron in the first case. In the new experiment it will be assumed that internal, combustion produces 155,000 calories per ton. The total energy of coal and stock is dissipated in many ways: (1) Lost in unburned carbon in producer ash. (2) Absorbed in internal reactions in the producer. (3) Lost as sensible heat in producer gases. (4) Absorbed by the metal in heating and melting. (5) Lost as sensible heat in waste gases from furnace. (6) Lost in excess air from furnace. (7) Lost in unburned hydrogen and carbonic oxide. (8) Lost by radiation and conduction. Some of these losses are without compensation, such as the carbon in the ash and the radiation; some are useful, such as the absorption by internal reactions; some are utilizations, like the absorption of heat in melting. In order, to find the proportion of energy utilized * The Physical and Chemical Equations, of the Open-Hearth Process. Tram, A. I, M. Jf,, Vol. XIX. t Chemiach-Calorische Untersuchungen uber Oeneratoren und Martinofen von Hanns V, Jiiptner und Friederich Toldt.